no-no

The term 'no-no' is a modern English reduplication, a playful and emphatic repetition of the simple negative 'no'. The base word 'no' has a deep Germanic lineage, tracing back to Old English 'nā', itself from the Proto-Germanic 'nai' (never) and ultimately from the Proto-Indo-European particle 'ne' (not). This process of reduplication, common in child language and informal speech, intensifies the concept of prohibition. By the mid-20th century, 'no-no' became lexicalized as a noun, concretely naming any act or thing that is explicitly forbidden or socially frowned upon, thus transforming a basic negation into a label for a taboo.

This is a reduplication of the English word 'no', which originates from Old English 'nā', a compound of 'ne' (not) and 'ā' (ever). It functions as a repeated negative particle to form a compound noun.